This Wednesday is an Earth Day with a difference. Our country and world are in the worst economic recession since the Depression, while, at the same time, global warming continues to be the biggest threat to our planet, other than nuclear war. Its a double whammy of epic proportions.

Which is precisely why going green now makes more sense than ever. By increasingly moving toward sustainable, nonpolluting energy, reducing overall energy usage and recycling and reusing resources, we can cut down on carbon emissions and pollution, as well as costs.

A New York Times Magazine article on Sunday, Why Isnt the Brain Green? raised insightful questions about why more people arent concerned about global warming and, in turn, leading a green lifestyle to help address the problem. Citing recent studies, the article stated that humans have a limited amount of things they can worry about, and that some worries are more immediate and physical, while others  like climate change  are, for many people, merely analytical.

Ultimately, the article argued, the best way to make sure we as a people go greener is for our communities and government to get involved. While individuals might not recognize or acknowledge the immediate pressing need for recycling, for example, government  based on a collective decision-making process  takes the longer-range view, and seeing that recycling is necessary, legislates it.

Mayor Bloomberg, with his PlaNYC, a far-reaching initiative to make the city both more sustainable and livable by instituting green practices, is a good example of a politician using his office to advance progressive and intelligent ideas on energy and the environment. Hybrid taxis and an improved anti-idling law are also helping make our air cleaner to breathe.

Similarly, the revision of the states bottle deposit law to include bottled water is an excellent step to cut plastic waste while also generating revenue.

As individuals and as members of local community groups, we ourselves all can do our part in making our city more energy efficient and, in the end, a healthier place to live.

New York University is leading the way with its significant cogeneration and composting operations. N.Y.U. has the citys first bike share program, encouraging cycling  nonpolluting transportation that is also good exercise. N.Y.U. is also effectively using the reward system  offering a party to the university residence hall that cuts its energy use the most.

The Cooper Unions new laboratory building on Cooper Square is being built to the highest LEED standards, and will be 40 percent more energy efficient than similarly sized buildings.

The Lower Eastside Girls Clubs new Avenue D building, not only will be green, but will serve as an educational incubator for local youth, teaching them how to incorporate sustainable practices into their families lives.

Likewise, P.S. 41 is moving closer to getting its own green roof, which will serve as an eco-lab for its elementary schoolers.

On a personal level, while we dont have to be as extreme as the Villages own No Impact Man, we can learn from his example, and from that of the Lower East Side Ecology Center, which has been leading the way for years on sustainability. Composting isnt hard, and is a great way to cut down on waste. Riding a bike, or just not running air conditioners in an empty apartment are ways to improve the environment. Going to an outdoor Greenmarket is a fun way to shop locally, supporting area farmers while cutting down on the carbon footprint of food miles. Recycling old computers and electronics is important, too, since this keeps toxic chemicals from leaching into our ground, water and food chain.

One of the simplest and most effective things one can do to improve the environment is to plant one or more trees on ones block. Part of the mayors PlaNYC, its as easy as a mouse click at www.milliontreesnyc.org.

Through a combination of government legislation, community planning and individual actions, we can work to save our world, and make it a better, sustainable one. Small steps can add up to a big difference.